1. Field of the Invention
The present invention relates to an optical data storage, and more particularly, to a cantilever-type near-field probe capable of easily improving an optical throughput and being applied to a head of an optical data storage and a method of manufacturing the same.
2. Background of the Related Art
Generally, it is widely known in that in order to store more optical data per unit area in an optical data storage a wavelength of a recording optical source has to be shortened and numerical apertures of a condensing lens have to be increased.
Although shortening the wavelength of recording optical source and increasing numerical apertures of condensing lens, since a next-generation data storage requiring a high density record has a limit of increasing the recording density due to diffraction of a light, there are proposed some alternative techniques such as a scanning probe recording (SPR) technique using a probe of atomic force microscope (AFM), a super resolution medium technique, a technique utilizing a near-field optical fiber probe overcoming the diffraction of the light, and so forth.
The near-field optical fiber probe has some drawbacks in that it is easily broken due to its mechanical weakness and it is difficult to arrange a number of probes at once. In addition, in case of the aperture of 100 nm, the throughput of light exited through the aperture is very small as a range of about 10−5 to about 10−7. Therefore, it is difficult to improve recording and processing speed of the optical data to such an extent that it is practically used.
In order to overcome the drawback of the conventional optical fiber probe, a new probe having several apertures has been developed through a common process of manufacturing a semiconductor device. However, since the throughput of light exited through the aperture is up to 10−5, like as the conventional optical fiber probe, there is necessity for increasing the throughput. Therefore, in order to increase the throughput of the aperture formed at the distal end of the probe, a method of exciting a plasmon mode and a method of minimizing the optical loss region generated from one wavelength dimension of the distal end of the probe have been proposed.
According to the method of exciting the plasmon mode, since an exciting efficiency of the plasmon mode is depended upon polarization and wavelength of an incident light, it is difficult to effectively excite the plasmon mode. In addition, there is another problem requiring an additional structure to excite the plasmon mode.
The method of minimizing the optical loss region is introduced by the conventional optical fiber probe, in which the probe is manufactured to have a structure of a large cone angle at the distal end thereof through a multi-stage wet etching process, a primary taper region of the probe is provided with a reflective film to reflect the incident light, a secondary taper region of the probe has a large cone angle consisting of the reflective film to maximally reduce the optical loss region, and a third taper region of the probe is to have a very small aperture of a probe shape, thereby providing the aperture of a high throughput.
However, the method of minimizing the optical loss region has drawbacks that the dimensions of the aperture depends upon the size of the primary taper region, and the aperture is manufactured through the multi-stage wet etching process, thereby complicating the manufacturing process.